Alpha 1-antichymotrypsin

Serpin peptidase inhibitor, clade A (alpha-1 antiproteinase, antitrypsin), member 3
PDB rendering based on 1as4.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1AS4​, 1QMN​, 2ACH​, 3CAA​, 3DLW​, 4CAA​
Identifiers
Symbols	SERPINA3 ; AACT; ACT; GIG24; GIG25
External IDs	OMIM: 107280 MGI: 105045 HomoloGene: 111129 ChEMBL: 5960 GeneCards: SERPINA3 Gene
Gene ontology Molecular function • DNA binding • serine-type endopeptidase inhibitor activity • protein binding Cellular component • extracellular region • extracellular space • intracellular • nucleus • extracellular exosome • blood microparticle Biological process • acute-phase response • inflammatory response • negative regulation of endopeptidase activity • regulation of lipid metabolic process • maintenance of gastrointestinal epithelium Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	12	16625
Ensembl	ENSG00000273259	ENSMUSG00000066361
UniProt	P01011	P29621
RefSeq (mRNA)	NM_001085	NM_008458
RefSeq (protein)	NP_001076	NP_032484
Location (UCSC)	Chr 14: 94.59 – 94.62 Mb	Chr 12: 104.15 – 104.15 Mb
PubMed search

Alpha 1-antichymotrypsin (α₁AC)^[1] is an alpha globulin glycoprotein that is a member of the serpin superfamily. In humans, it is encoded by the SERPINA3 gene.

Function

Alpha 1-antichymotrypsin inhibits the activity of certain enzymes called proteases, such as cathepsin G that is found in neutrophils, and chymases found in mast cells, by cleaving them into a different shape or conformation. This activity protects some tissues, such as the lower respiratory tract, from damage caused by proteolytic enzymes.^[2]

This protein is produced in the liver, and is an acute phase protein that is induced during inflammation.

Clinical significance

Deficiency of this protein has been associated with liver disease. Mutations have been identified in patients with Parkinson disease and chronic obstructive pulmonary disease.^[3]

Alpha 1-antichymotrypsin is also associated with the pathogenesis of Alzheimer's disease as it enhances the formation of amyloid-fibrils in this disease.^[2]

Interactions

Alpha 1-antichymotrypsin has been shown to interact with DNAJC1.^[4]

References

1. Logan, Carolynn M.; Rice, M. Katherine (1987). Logan's Medical and Scientific Abbreviations. Philadelphia: J. B. Lippincott Company. p. 3. ISBN 0-397-54589-4.
2. Kalsheker N (1996). "Alpha 1-antichymotrypsin". Int. J. Biochem. Cell Biol. 28 (9): 961–4. doi:10.1016/1357-2725(96)00032-5. PMID 8930118.
3. "Entrez Gene: SERPINA3 serpin peptidase inhibitor, clade A (alpha-1 antiproteinase, antitrypsin), member 3".
4. Kroczynska B, Evangelista CM, Samant SS, Elguindi EC, Blond SY (March 2004). "The SANT2 domain of the murine tumor cell DnaJ-like protein 1 human homologue interacts with alpha1-antichymotrypsin and kinetically interferes with its serpin inhibitory activity". J. Biol. Chem. 279 (12): 11432–43. doi:10.1074/jbc.M310903200. PMC 1553221. PMID 14668352.

Further reading

• Janciauskiene S, Wright HT (1999). "Inflammation, antichymotrypsin, and lipid metabolism: autogenic etiology of Alzheimer's disease.". BioEssays 20 (12): 1039–46. doi:10.1002/(SICI)1521-1878(199812)20:12<1039::AID-BIES10>3.0.CO;2-Z. PMID 10048303.
• Kalsheker N, Morley S, Morgan K (2002). "Gene regulation of the serine proteinase inhibitors alpha1-antitrypsin and alpha1-antichymotrypsin.". Biochem. Soc. Trans. 30 (2): 93–8. doi:10.1042/BST0300093. PMID 12023832.

External links

• The MEROPS online database for peptidases and their inhibitors: I04.002
• Alpha 1-antichymotrypsin at the US National Library of Medicine Medical Subject Headings (MeSH)